> treating API tokens as compromised the moment you pasted them into an AI chat seems a reasonable default in general.

Coding agents in my experience alert you to this, which is good. I pasted what was temporary token I made into Claude, just to test something, and after it had done the task it said something like, "you gave me a live token to work with in the chat, I'd advise you to treat that as exposed and rotate it."

It would be a good standard for all chat interfaces to have those "alerts" built in.